Clare Research Has Far-Reaching Impact

March 2012By Trevor Elliott, Ole Martinsen

American Association of Petroleum Geologists (AAPG)

The onset of geological research that underpins the Clare Basin’s present importance as a research and training area for the hydrocarbon industry commenced in the 1950s via biostratigraphic studies of the Clare Basin-fill by Frank Hodgson and a legion of Ph.D. students, most notably Gillian Lewarne. She established the biostratigraphy of the early deepwater shales (Clare Shales) that overlay the Carboniferous/Mississippian Limestone and record a prolonged period of deepening stratigraphy that preceded deposition of the turbidite sandstones (Ross Formation).

She also established, along with colleagues the biostratigraphic framework for the younger fluvio-deltaic deposits of the basin fill.

This time- and correlation framework – based on what we would now call condensed sections – became an essential template for subsequent research that exists to this day.

Subsequently Dan Gill, geology professor at Trinity College Dublin and later at Imperial College, University of London, became interested in the Clare area. Suspecting that parts of the basin-fill succession could be deepwater turbidites, he invited Philip Kuenen, one of the fathers of deepwater and turbidite sedimentology in the 1950s, to Clare. Their work resulted in a 1958 publication on the area’s famous sand volcanoes.

Gill invited Lewarne to join him as a teaching assistant in Trinity College. On transferring to Imperial College he appointed Ph.D. student Malcolm Rider with the task of unraveling the sedimentology of the Clare Basin fill.

Rider submitted his Ph.D. in 1969 and subsequently published his findings in several journals, but his 1978 paper in the AAPG BULLETIN is a classic paper where he highlighted the comparison of the Clare sedimentary rocks to the Gulf of Mexico basin.

The thesis itself is a remarkable document. It establishes the depositional settings for each of the stratigraphic units of the basin fill over the entire basin remnant. Each depositional setting was treated in depth via meticulous observations and well-reasoned, logical interpretations.

It was a benchmark Ph.D. thesis for its time and underpins the vast majority of subsequent work on the basin fill.

Included in the thesis is a chapter of the sedimentology of the modern Mississippi delta. Rider had identified the youngest part of the basin fill – the Central Clare Group – as the product of large prograding deltas that he felt were broadly similar to the Mississippi delta.

Not content with reading the published literature on the delta, he boarded a cargo ship bound for New Orleans and worked his passage across the Atlantic, eventually arriving completely unannounced at Louisiana State University, where he negotiated a short-term research opportunity in the university with leading researchers who had worked the Mississippi delta.

That resulted in the AAPG BULLETIN paper that has been influential literature way beyond the Clare Basin – and not least for relating modern depositional environments to ancient rock successions.

Going Global

Trevor Elliott met Malcolm Rider at the 1975 IAS Congress in Nice, France, and over a lunch asked if he could undertake research in the Clare Basin in order to extend some of Rider’s work.

Rider agreed and a new phase of research commenced that ultimately led to the initiation of training courses for the oil industry in the area.

Also at the Nice Congress, John Collinson, then at the University of Bergen, aired the possibility of a training consultancy for the industry with Elliott.

Agreement was reached and Harold Reading, winner of the AAPG Distinguished Educator Award in 1997, and Collinson’s and Elliott’s former supervisor, also was included in a partnership named Sedimentary Research Associates.

Soon the Clare Basin became the partnership’s flagship annual course, and the global use of the Clare Basin as a training ground was established.

During this period AAPG member Andy Pulham did his Ph.D. research on the deltaic deposits of the basin fill supervised by Elliott, and Ole J. Martinsen did his master’s study of the slope component of the basin fill supervised by Collinson.

For Martinsen, winner of the AAPG Robert R. Berg Outstanding Research Award in 2011, the Clare Basin work has been the fundament of the later career in industry and research.

As understanding of the basin-fill developed further via these and other research projects, the Clare became increasingly recognized internationally – including among several major oil companies – and its use in the training oil company geoscientists became global.

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